Method and apparatus for capsulating liquids



July 6, 1943.

C. L. WECKE SSER METHOD AND APPARATUS FOR GAPSULATING LIQUIDS 4Sheets-Sheet 1 Filed Aug. 12', 1940 I FIGJ.

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CHARLES L.WECKE$$ER y my /W+8M ATTORNEY$ y 1943. c. L. WECKESSER METHODAND APPARATUS FOR CAPSULATING LIQUIDS Filed Aug. 12, 1940 4 Sheets-Sheet2 INVENIOR. MZLES L. WECKESSER ATTORNEYS July 6, 1943. c. WECKESSER2,323,581

METHOD AND APPARATUS FOR CAPSULATING LIQUIDS V Filed Aug. 12, 1940 4Sheets-Sheet 3 INVENTOR.

B CHARLES L'..WECKES$ER i mmm MW ATTORNEYS July 6, 1943. c. L. WECKESSERI METHOD AND APPARATUS FOR CAPSULATING LIQUIDS Filed Aug. 12, 1940 4Sheets-Sheet; 4

I INVENTOR.

' CHARLES L.WEOKESSER BY 2 a 42% F 2g ATTORNEYS zdE Patented July 6,1943 METHOD AND APPARATUS FOR CAPSULAT- ING LIQUIDS Charles L.Weckesser, Detroit, Mich., assignor to C. E. Jamleson & Com

7 pany, Detroit, Mich., a corporation of Michigan Application August 12,1940, Serial No. 352,319

12 Claims.

The invention relates to the manufacture of liquid medicamentfllledgelatin capsules and forms a continuation in part of my pendingapplication for patent Serial No. 191,793, filed February 21, 1938. Theinvention consists in certain novel features in the method and theapparatus, as hereinafter set forth.

In the drawings:

Figure 1 is a front elevation of the machine;

Figure 2 is a plan view thereof;

Figure 3 is an enlarged vertical longitudinal section partly inelevation through the holder forming and capsule forming rolls;

. strip to the capsule forming mechanism. p

Figures 4 and 5 are sections similar to Figure 3 I showing successivepositions in the forming of a capsule;

Figure 6 is an axial section through one of the holder forming rolls;

Figure 7 is a similar view through one of the capsule forming rolls;

Figure 8 is an enlarged section through a portion of the capsule formingroll, showing one of the capsule forming pockets;

Figure 9 is a front elevation of Figure 8; Figure 10 is a plan view ofthe pair of holder forming rolls;

Figure 11 is an 'end elevation of the machine with some of the partsbroken away. Y

In the present state of the art of forming medicament liquid filledgelatin capsules, registering half capsules are formed in a pair ofopposed gelatin strips having the medicament liquid therebetween, saidstrips being then pressed to-" ether to exclude the surplus liquid andto weld the capsule sections to each other. In the carrying out of suchamethod it is very essential that the gelatin strips should be in theproper con dition of plasticity,v boh for the forming of the of arevolving drum B, and while traveling therewith is solidified to formthe strip C. This strip is passed over rolls D and D, which oil theopposite surfaces thereof prior to delivery to the capsule formingmechanism. A similar strip forming mechanism simultaneously delivers asecon Capsule forming mechanism This mechanism comprises a pair of rollsE and E for forming a liquid holder and a pair of capsule formingdierolls F and F arranged therebeneath. The holder forming rolls havecylindrical portions lit at opposite ends thereof with a central portionE of smaller diameter and tapering portions E connecting the portions Eand E There is also a rib E on each of the v portions E which serves toseal the marginsof pockets therein and for eflecting a sealing weldtherebetween; It is, therefore, cneof the features of my improvement toprovide'means for insuring such proper conditioning of the gelatinstrips at the time when these operations are performed thereon. Anotherfeature of my improvement is themeans for introducing and holding theliquid between the strips during the capsule forming opera ions. Other,features of my improvement relate to the construction of various jportions of the apparatus, as. here forth. j v

The gelatin strips may be formed in the usual ina'fter set way bydepositing the liquid gelatin upon a traveling surface maintained atproper temperature to cause solidification. 'As shown, the liquidgelatin in a receptacle A is deposited on the periphery the strips toeach other so as to temporarily form thereof a holder. The peripheriesof the portions E of the two rolls are sufficiently spaced to leave anopening for the insertion of a conduit. through which the liquidmedicament is introduced.

Therolls F and F are directly beneath the rolls E and E and serve toclose the bottom of the holder portion of the. strips so as to retainthe liquid content. In addition to this function, the rolls F and F areprovided with registering pockets F in which the individual capsule areformed, said pockets being arranged in-circum ferential and transverseseries so as to cover the greater part of the periphery. Each pocket issurrounded by an annular flange F which in cooperation with theregistering flange of the other roll progressively welds the liquidfilled capsule portions to each other and severs the same from thesurrounding portions of thestrips. There is suflicient space between theflanges of adjacent pockets to leave a continuous web or net'which willbe fed downward by the rotation of the rolls I into-a -suitablereceptacle. On the other hand,

. thecapsules will be retained in one or the other of the registeringpockets from which they may later'be expelled 'as'hereinafter',described. p Y A'sabove stated, the successful performanceof thesuccessive steps in forming the capsule is dependent upon maintainingthe proper condi:

tion in the gelatin strips which is accomplished as follows. All of throlls E, E, F and F have their peripheral portions maintained at .apredetermined temperature so that the temperature of the gelatin stripsin contact therewithwill be exac ly. controlled. I have found that theholder forming rolls should be maintained at a temperature between 90 F.and 100 F., preferably 95 F. If the temperature is too low a very raggedand imperfect seal is made between the marginal portions of the strip,whil on the other hand, if the temperature is too high the gelatin willstick to the rolls and will be so weakened as not to satisfactorily holdthe medicament. The die rolls should be kept at a temperature between 80F. and 90 F., while the medicament liquid which is to be filled into thecapsules should be between the limits of 80 F. and 100 F. Suchtemperatures are maintained by forming the roll hollow and circulatingtherethrough a heating liquid. As shown in Figure 1 and 2, the liquidcirculating medium, preferably a hydrocarbon oil, is held in a tank Gwhich is divided into several compartments G, G and G Heating means isprovided for each of these compartments, preferably electrical heaters,which are automatically controlled by thermostatic means. As shown, H,H, etc., are the individual heating, controlling and indicating devicesfor the several tanks, which are mounted on a panel where they may beobserved by the attendant and adjusted when necessary. As the detailedconstruction of these devices forms no part of the instant invention, itis not completely illustrated. The compartments G, G and G are connectedby circulating conduits I with the different parts of the apparatus inwhich the temperature is to be controlled. There are also individualpumps J, J and J for propelling the fluid from each compartment, saidpumps being simultaneously operated, preferably by an electric motor JThe fluid from the compartment G is circulated through a jacket Asurrounding the liquid gelatin receptacle A, so as to maintain thisreceptacle at the proper temperature. The fluid from the compartment Gis circulated through the capsule forming rolls and the fluid from thecompartment G is circulated through the holder forming rolls. To insureuniform temperature in all of the gelatin contacting portions of each ofthese rolls they are preferably constructed as follows. The rolls E andE are formed with an outer shell E having heads E" and E at oppositeends thereof. E is a tubular shaft extending axially through the heads Eand E and E is an inner tube extending part way through the tubularshaft E The liquid propelled by the pump enters through the tube E whichconducts it to the head E". Here it passes into the tube E and throughports E in said tube and the head E into the annular chamber between theshaft E and shell E The tubular shaft E forms the outlet for the fluidwhich passes from the annular chamber through ports E in the head E intothe interior of said tubular shaft. A plug E closes the outer end of thetubular shaft 12. and a bushing E between the tubes E and lit preventsany short-circuiting of the fluid. Thus, the heated fluid is compelledto traverse the whole length of the annular chamber within the shell Ethereby heating said shell to the desired temperature for contact withthe gelatin strips.

The rolls F and F are heated in a similar manner by passing the heatingfluid through a chamber within the outer shell of the roll. These rollsare, however, more complex in their construction to enable them toperform a number of distinct functions, the construction being asfollows.

The primary function of the rolls F and F is to form in the gelatinstrips the registering half capsule portions, which are filled with themedicament and then sealed to each othe The gelatin is expanded into thepocket I" by suction combined with the hydrostatic pressure of theliquid content in the holder. It is, therefore, necessary to applysuction to the pockets at a predetermined point in the revolution of theroll to cut of! this suction when the gelatin is expanded to the desiredamount, and flnally after the sealing of the complementary capsulesections to each other, to eject the capsule from the pocket bysuper-atmospheric pressure. For convenience in manufacture, I preferablyform the roll F and F of an outer shell portion F, having its outerperipheral surface machined to form therein the pockets F and thesurrounding annular flanges F. This outer shell is mounted on an innerannular member F which latter is revolubly mounted, preferably by ballbearings F, on an inner non-revoluble hollow shaft member I". The shaftF together with an inner tube F forms a means of circulating the heatingfluid through the roll in the same manner as with the rolls E and E.

The pockets F are arranged in axially extending rows which alternatelyare in staggered relation so as to cover the greater part of theperipheral area. Each pocket forms a substantially cylindrical recesshaving a central post F extending outward from the bottom, and a passageF in this post extending completely through the shell F. The member F isformed with a series of axially extending grooves F in its peripheralsurface each of which registers with all of the passages F in a singleaxially extending row of pockets. The grooves F extend through one endof the row but terminate short of the other end. A non-revoluble head Kmounted on the shaft F forms sealing contact with one end of the membersF and F. This head has a segmental groove K in its contacting surfacelocated to communicate successively with the grooves F during therotation of the roll. The groove K is connected by passages within thehead K to a hollow post K connected by conduits to a source of suction(not shown). A second hollow post K is'connected with a source ofcompressed air, and a passage leading from this post through the head isconnected with a port K with which the grooves F" are successivelyregistered. The grooves K are so located that suction will becommunicated with each row of pockets in the descending portion of theperiphery of the rolls a short distance above the horizontal plane ofthe axes of said rolls. Thus the gelatin strip will be expanded intoeach pocket of the row until it contacts with the post F at which timethe passage 1'" will be sealed to prevent further exhaustion of the airwithin the pocket. This gauges the size and capacity of the capsulesection, while still permitting a slight expansion incident to theclosing and welding of the two complementary sections to each other. Theexact location of the port K is not so important as its function ismerely to dislodge the complete capsule from the pocket. I have shownthe port slightly before the lower dead center of the roll.

The fimction of the flanges F is two-fold, first, they progressivelypress the capsule sections together and into welding contact; and

it preferable to form such flanges on both rolls. It is also importantthat these flanges should be accurately fashioned. The outer surface ofeach flange must be concentric with the axis of the roll and incooperation with the corresponding flange of the complementary roll willprogressively squeeze out the gelatin therebetween. The forward side ofthe flange in the direction of travel of the rolls will squeeze thegelatin toward the pocket so as to form a wall of full thickness in thecapsule. There is, however, danger that on the trailing side the capsulemay be severed from the strip wi hout forming a wall of full thicknessor even wit out forming a complete closure. This is for the reason thatthe approaching surfaces on the trailing side are at such an angle toeach other as to force the gelatin therebetween away from the pocket,whereas the approaching surfaces on the forward side are at an angle toforce the gelatin toward the pocket. I have avoided this difiiculty bychamfering or cutting away the flange on the trailing side of thepocket, so as to form oblique surfaces that will force the squeezed outgelatin toward the pocket instead of away from it. Thus, as shown inFigures 8 and 9, the chamfer I2 is greatest at the center of thetrailing edge of the pocket and progressively narrows to die out at theopposite Side of the pocket. Such construction I have found will form acap sule with full thickness of wallon its trailing side.

The rolls E, E and F, F are driven at substantially the same peripheralspeed by any suitable construction of transmission mechanism. Thisincludes the intermeshing gear wheels L and L on the rolls F and F,which hold these rolls in proper registration, and the intermeshing gearwheels L and L for the rolls E and E. 1

Operation In carrying out my improved process with the mechanism asabove described, the gelatin strips C and C formed respectively on thedrums B and B are led over and under the oiling rolls D and D to theholder forming rolls E and E', thence downward between the rolls F andF. After the machine is in full operation these strips will be formedinto a holder while passing around the rolls E and E, their marginaledges being welded to each other by the ribs E so as to form aliquid-tight seal. Also, the portion of the strips passing between therolls F and F are pressed together to form a bottom seal. Consequently,the medicament liquid may be fed into. the holder through a conduit Mand maintained at a predetermined level therein. The conduit M extendsto a tank M in which the liquid medicament is stored and maintained atthe desired temperature. Suitable means, such as a valve M in theconduit M, will regulate the flow. Thus, the hydrostatic pressure of theliquid in the holder will bend the strips forming the opposite sidesthereof into conformity to the surface of the rolls F and E, while thesuction applied to the pockets will expand the portions of the stripcovering the same un-til suction is cut off by sealing contact with thepost F Liquid within the holder will fill the capsule sections as theyare formed so that when in their downward travel they are pressed inwelding contact with each other a measured quantity of liquid will beenclosed, the surplus liquid being forced outward and upward in theholder. However, after the closing of the orifice at the trailing end ofthe pocket, there will still be a slight movement of the capsulesections toward each other without any opportunity to eject any portionof the liquid content. As the liquid is incompressible it must beprovided with some place to go which with my construction is the portionof the pocket surrounding the post F In the further advancement of therolls F and F the channels F are registered with exhaust ports K throughthe heads K which restores atmospheric pressure in the pockets FSubsequently, these channels are registered with the passages Kadmitting air at more than atmospheric pressure, which will eject thecapsules from the pockets. As frictional resistance is not exactlybalanced in the complementary pockets, some of the capsules will remainin the pockets of one roll while others will remain in the pockets ofthe other roll. This is immaterial as both rolls are provided withcapsule ejecting means. Theejected capsules will drop on an inclinedchute N which will direct them into a suitable receptacle N.

While the medicament may be supplied to the holder through the singleconduit M, as above described. I find it preferable to provide acirculatory system through which the medicament in the storage tank M iscontinuously fed into the holder and back again into the tank. Thus,

as shown, a second conduit M extends down-' ward into the holder withits lower end placed at a predetermined height. This conduit withdrawsthe medicament through the operation of a circulating pump M and returnsit to the tank M. Such construction has the advantage, first, it can beused to accurately control the level of liquid in the holder and,consequently, the hydrostatic pressure which is exerted against thegelatin while the capsule is being formed; second, it keeps the reserveliquid in the holder at a more constant temperature because it providesfor a continuous change of the liquid; and third, it provides forcirculation of the liquid which helps to keep any suspended matteruniformly distributed.

What I claim as my invention is:

1. In a process of forming liquid filled gelatin capsules, the steps offeeding a pair of gelat n strips downward between pocketed die rolls,heating the strips above said rolls to an exactly predeterminedtemperature, separating the central portions of said heated strips fromeachother, and pressing the marginal portions thereof together whileabove said rolls to temporarily form thereof a liquid holder, feedingliquid into said holder to a predetermined level, and expanding thewalls of said holder into the pockets of said die rolls to formcomplementary liquid filled registering capsule portions which aresealed together when passed between said rolls.

2. In a process of forming liquid filled gelatin capsules, the steps offeeding a pair of gelatin strips downward between pocketed die rolls,heating said strips above said die rolls to an exactly predeterminedtemperature, pressing the margins of said heated strips together whilestill above said rolls and maintaining the central portions thereofspaced to temporarily form a liquid holder, feeding liquid into saidholder to a predetermined level, expanding the walls of said holder intothe pockets of said rolls to form registering liquid filled. capsuleportions which are sealed together while passing between said rolls, andmaintaining said strips while passing between said die rolls at apredetermined temperature slightly less than that of the strips abovesaid rolls.

3. An apparatus for forming liquid filled gelatin capsules comprising apair of rolls between which a pair of gelatin strips are fed, said rollshaving registering pockets and annular portions surrounding said pocketsin rolling contact with each other, each of said annular portions beingflush with the inner surfac of the wall of the pocket on the leadingside thereof with respect to the direction of rotation of said rolls andbeing chamfered on the trailing side.

4. An apparatus for forming liquid filled gelatin capsules comprising apair of rolls between which a pair of gelatin strips are fed, said rollshaving series of registering pockets, annular portions surrounding saidpockets in rolling contact with each other and portions between saidannular portions providing clearance for the thickness of said strips,the inner surface of the wall of each pocket being normal to the rollingsurface of said annular portion at the point of intersection therewithon the leading side thereof with respect to the direction of rotation ofsaid rolls and the inner surface on the trailing side at the point oi.intersection with the rolling surface being at an oblique angle to forcethe displaced gelatin toward said pocket.

5. In a process of forming liquid filled gelatin capsules, the steps offeeding a pair of gelatin strips downward between die rolls havingregistering pockets therein, sealing together the marginal portions ofsaid strips above said rolls to temporarily form thereof a liquidholder, feeding into said holder the liquid medicament from a source ofsupply maintained at a predetermined temperature, withdrawing a portionof the liquid .from said holder and returning the same to the source ofsupply whereby said liquid is constantly circulated and held at apredetermined level within the holder, expanding the portions of saidstrips in contact with the liquid into the pockets of said rolls to formregistering liquid filled capsule portions, closing together saidcapsule portions and severing the same from said strips.

6. In an apparatus for forming liquid filled gelatin capsules, a pair ofdie rolls having series of registering pockets therein, means forfeeding a pair of gelatin .strips downward between said rolls, means forpressing together and sealing the margins of the portions of said stripsabove said rolls to form thereof a liquid holder, a container for liquidmedicament, a conduit for feeding the liquid medicament from saidcontainer into said holder, a second conduit extending from saidcontainer into said holder, and means for withdrawing a portion of theliquid through said second conduit and returning the same to saidcontainer whereby the liquid in said holder is circulated to maintainthe same at a constant temperature and also to maintain a constanthydrostatic level.

7. In a process of forming liquid filled gelatin capsules, the steps offeeding a pair of gelatin strips downward between relatively movabledies having complementary registering pockets therein, sealing togethermarginal portions of said strips above said dies to temporarily formthereof a liquid holder, introducing liquid into said holder to form apool, expanding into said pockets the portions of said strips inregistration therewith to form liquid filled complementary capsuleportions, and closing said complementary dies to seal together saidcomplementary capsule portions and to sever the same from said strips.

8. In a process of forming liquid filled gelatin capsules, the steps offeeding a pair of gelatin strips downward between rotary die rollshaving registering pockets therein, sealing together the marginalportions of said strips above said die rolls to temporarily form thereofa liquid holder, introducing liquid into said holder to form a pooltherein and to spread said strips over pockets in said rolls byhydrostatic pressure, expanding into said pockets the portions of saidstrips covering the same to form liquid filled complementary capsuleportions, and closing together said complementary capsule portions andsevering the same from said strips by the continued rotation of said dierolls.

9. In a process for forming liquid filled gelatin capsules, the steps offeeding a pair of gelatin strips downward between rotary die rollshaving registering pockets therein, sealing together the marginalportions of said strips above said rolls to temporarily form thereof aliquid holder, introducing liquid into said holder to form a pooltherein and maintaining said pool at a constant level to spread saidstrips over the pockets in said rolls by a predetermined hydrostaticpressure, expanding into said pockets the portions of said stripscovering the same to form liquid filled complementary capsule portions,and closing together said complementary capsule portions and severingthe same from said strips by the continued rotation of said die rolls.

10. In a process of forming liquid filled gelatin capsules, the steps offeeding a pair of gelatin strips downward between rotary die rollshaving registering pockets therein, sealing together the marginalportions of said strips above said die rolls to temporarily form thereofa liquid holder, introducing liquid at a predetermined temperature intosaid holder to form a pool therein and maintaining a substantiallyconstant temperature in the liquid in said pool to condition theportions of gelatin strips in contact therewith, expanding into saidpockets the portions of said strips covering the same to form liquidfilled complementary capsule portions, and closing together saidcomplementary capsule portions and severing the same from said strips bythe continued rotation of said rolls.

11. In an apparatus for forming liquid filled gelatin capsules, a pairof rotary die rolls having complementary series of registering pocketstherein, means for directing a pair of gelatin strips downward betweensaid die rolls, means for sealing together the margins of said stripsabove said die rolls to temporarily form thereof a liquid holder, meansfor introducing liquid into said holder to form a pool therein and tospread said strips over the pockets in said rolls by hydrostaticpressure, and means for applying suction to said pockets to expand theportions of said strips covering the same and to form complementaryliquid filled capsule sections adapted to be sealed together and severedfrom said strips during the continued rotation of said die rolls.

12. In an apparatus for forming liquid filled gelatin capsules, a pairof rotary die rolls having complementary series of pockets therein, a

pair of rolls above said die rolls, over around and between portions ofwhich a pair of gelatin strips are fed and thence downward between saiddie rolls, means for sealing together the margins of said strips abovesaid die rolls to and severed from said strips during the continuedrotation of said die rolls, means for maintaining the upper rolls at apredetermined temperature to condition the strips passing thereover, andmeans for maintaining the die rolls at a slightly lower temperature.

CHARLES L. WECKESSER.

